cbuzzetti wrote:
Hi Eric, are the numbers below for the 09-10 Miller Nationals numbers that you got from Ryan or are these numbers from the internet? If the 143 number shown is one you got from me or from a post I made that was from 2010 At Buttonwillow before Nationals and should not be used he as a comparrison. That same car at Nationals at Miller dynoed at 137. I was using this as a comparison for variations in dynos.
This was also a car that had a head on it that became illegal after Nationals based on the head thickness rule. I installed a Milledge head after Nationals to keep in compliance with the new rules for heads. The car HP did not change.
I am also unclear about the HP ratings for the 2012 Nats. You have 141, 140.5 and 136 listed. In a post made today you are quoting smaller numbers for your car. Please clarify.
Thanks,
Sterling Doc wrote:
Charlie, I'll do my best. I was not at Miller, and did not see every dyno there, so those years are less clear.
2007 - 137, 135 (few dynos done)
2008 - 139 (first "pro-built" motor), 137 (still few dynos, second pro built motor blew up before tested)
2009, 2010 (Miller) 143, 139 (may be others)
2011 - 139, 138, 135
2012 - 141, 140.5, 136
With Nationals back at Miller, we expect a bigger turnout, and a bigger number of highly tuned cars for 2013.
This only represent cars that showed up at Nationals, not all the dynos we see and evaluate.
What question do have on the formula?
At the suggestion of John Brown, I changed how it was typed to be more mathematically correct, but it should be clear.
Altitude
.
Altitude is an important factor that most of us ignore, yet it affects the engine’s performance possibly more than any other element. The general formula for power loss with increases in altitude is 3 percent for every 1,000 feet above sea level. If you race in Colorado at 5,000 feet instead of in California at sea level, you can expect to lose about 15 percent of the engine’s potential power output, if the engine is tuned properly.
Air is thinner at higher altitudes, which means there’s less fuel-burning oxygen than at sea level. You might sense a common theme here: less air (oxygen) means less fuel to maintain the proper air/fuel ratio. So, running at higher altitudes requires a leaner mixture setting than running at sea level.
So if you were making 137 at 4000ft altitude well then you are making really big power at sea level.